1. Field of the Invention
This invention relates to a thermal transfer printing apparatus, and more particularly to a thermal transfer printing apparatus of the type in which a peel angle between ink paper and printing paper can be large.
2. Description of the Prior Art
In conventional printing apparatuses as disclosed in Japanese Patent Unexamined Publication Nos. 60-23078 and 60-27579, a peel guide and an ink supply guide are provided on a body of the apparatus. In such prior art, there is no clear disclosure of a peel mechanism for use with ink paper which employs a pigment or a dye and is capable of density gradation.
There has also been proposed a printing apparatus, as disclosed in Japanese Utility Model Unexamined Publication No. 2-94137, in which there is provided a ribbon peel mechanism for taking up or winding up a peeled ink ribbon through a guide roller.
In the above conventional printing apparatuses, however, consideration is not given to the force of peel of the ink paper from the printing paper, the amount of transfer of the ink, and wrinkles developing in the ink paper. Therefore, there have been encountered problems such as an excessive peel force, an insufficient transfer, uneven density, and wrinkles in the ink paper.
In addition, when the ink paper is to be set in position, much time and labor have been required for changing an ink paper supply roll and an ink paper take-up roll and for positioning the ink paper with respect to the thermal head. This is another problem with the prior art.